Change-over mechanism for valves, especially such of dry gas-meters



M. HELM Aug. 4, 1936.

CHANGE-OVER MECHANISM FOR VALVES, ESPECIALLY SUCH OF DRY GAS METERS Fild July 5, 19:55

Patented Aug. 4, 1936 Fries 'CHANGE-OVEE MECHANISM FOR VALVES, ESPECIALLY SUCH OF DRY GAS-METERS Max Helm, Berlin-Niederschonhausen, Germany,

assignor to Allgemeine Elektricitats-Gesellscl'iaft, Berlin, Germany a Application July 5, 1935, Serial No. 30,027

In Germany June 19, 1934 4 Claims.

' There exist valve change-over devices for gas- ---meters, in which the-change-over valve lever con- 7 tacts with lugs or segments and is guided by them -:unti1-the moment of thechanging-over of the 5&5 valves'so' that the changing-over itself takes place very quickly'by means of a spring. Said segments lock the change-over 'lever by their contact with it and thereby hold the closed valve firmly down ton-its-seat so that premature opening is prevented.

Valve change-over devices of the above-mentioned type operate satisfactorily at a certain zdefinite load of the gas-meter. If, however, the :load increases, the diaphragm of the gas-meter rf-moves-a greater distance sothat also the mem- -ber-bearingthe' lugs or segments, for instance atdisk affixed to ashaft turnedto and fro by the sdiaphragmofthe gas-meter, is-caused to turn "through a larger' angle. ,In such a case, the aggorchange-over lever of the valvemay not contact the said segments and be temporarily without any: guidance, in consequence whereof it may further occur-that the closed valve is pressed upon its seatnot firmly enough and, therefore, gas can escape-also through this valve, whereby :ythe measuring accuracy of the gas-meter is considerably' 'impaired. The change-over valve 1ever for-some cause, for instance owing to jame ming, the presence of dirt, or to slackening of go the change-over spring, or the like, after hav- =ing-part1y changed over, turns in the reverse di- "Iection; i. e. rearwardly, and remains'hangingin ,tan intermediate position so that both valves are open at-thesame time and nomeasuring at all 35 takes place. 3

Thepresent invention relates to a valve changezover .device intended especially for use in coni nection' with dry gas-meters and being so designed as-to prevent the above disclosed drawo40-backin the case of over-loading The gist of the --invention residestherein that, besides the lugs or ,tsegments, alsoa locking device is provided which after the change-over has taken place, retains the change-over valve lever in its new position :45 runtilit is; g'uided by a lug concerned. The in- =vention presents the advantage that even in the lease of the overloading and the corresponding -..larger. angular movement of saidlever this latterissecurely prevented from swinging back in the .direction of its former position and is then i retained'in an'intermediate position. 'In my improved device the changeover lever .is always held fast in the one or the other of .its two end 7 positionsas long asit is not guided by its asso- I ,e 55iciatedlug or segment. The valves are always either completely open or completely closed, so that gas can flow only through that valve which is open at the time being. The measuring accuracy and the reliability of the gas-meter is thereby considerably increased and rendered com- 5 pletely independent of theload on the gas-meter at that time.

The invention is illustrated diagrammatically and by way of example on. the accompanying drawing which shows several constructional 10 forms especially of the locking device. There are in all these forms two lugs orsegrnents, but other constructions are possible. .Essential in each case is that the change-over valve lever is held fast either by the segment or byalocking device de- 15 signed according to'this invention, the segment and the locking device alternating in holding fast said lever, which, therefore, is always located in the one or the other of its end positions.

The gas-meter proper and the diaphragm which forms apart of it have been omitted in a I the drawing.

Fig. la is a front-view of a change-over dey vice designed according to this invention, the partsbeing shown in' the positionthey assume just prior to the changing-over.

- Fig. lb is a similar representation, a few portions of Fig. 1a being omitted in this figure and the parts being shown in that position which they assume just after the changing-over. .30

Fig. 1c is a plan of part of the device, the position of the parts corresponding to that of Fig. 'la.

Figs. 2a., 2b, 'and'2c are views similar to those of Figs. 1a, lb, and 1c and show a modification, the positions of the parts in the threefigures core responding with those of Figs. la-lc.

Figs. 3, 3a, and 3b are views similar to those of Figs. 1a, lb, and 1c, and show another modification the position of the parts corresponding likewise with Figs.-1a, 1b, and 1c, and 40 Fig. 4 is a' representation of still another constructional form, all as fully described hereinafter.

Referring to Figs.- la, ligand 10, I denotes a shaft turned in a known manner by the diaphragm of the gas-meter through an angle, the size of which depends upon the load on said meter. Attached to the free end of said shaft is a circular disk 2 from which project, two oppositely located lugs or segments 3 and 3 4 denotes the change-over valve lever which is affixed to a shaft fi (Fig. la) connected with the valves .(not shown) of the gas-meter and actuating, i. e. changing-over, them. At the lower end of said lever is atransverse member 6 which is .55

the free end of the spring 8 slidably extends.

In Fig. 1c the spring 8 has been omitted.

On the outer side of the transverse member 6 is a wedge-shaped projection I3 having two oppositely located'oblique surfaces [4 and I5 (Fig.

10) which are moved alternately to the left and to the right together with, and by, the lever 4, according to the direction of motion of the same. Said surfaces l4 and I5 co-operate with a roll I9 attached to the free end of an arm I! hinged at the point [6 to a stationary part of the gas-meter, and there is also provided a helical tension spring 18 holding the roll|9 always in contact with the wedge shaped member I3. The spring 8 when tensioned is strong enough to overcome the resistance oifered by friction and the parts l3, 19.-

The manner of operation of this device is as follows:

In the position of the parts as shown in Fig. 1a. the lever 4 is in a position in which the guide nose 1' is just being disengaged from the lug or segment 3. Immediately thereafter the tension of the spring 8 becomes active, the spring straightens and turns the lever 4 with the transverse member 6 and the wedge 13 from the position of Fig. 1a into the position of Fig. 11), whereby the shaft 5 to which the lever 4 is secured is turned, the extent of this motion being such that one of the two valves (not shown) is closed and the other is opened.

If in consequence of over-loading the diaphragm of the gas-meter has turned the shaft I (Fig. 10) with the disk 2 and segments 3, 3 to such an extent that the guide-nose I cannot reach and contact the segment '3, then the lever 4 will not be retained by this segment in this position. In such circumstances this is now effected by the wedge l3 and thearm H with its roll l9, because the wedge l3 will move below said roll from the right to the left, bringing the roll upon the oblique surface M. It will'be obvious that the lever 4 will now be retained in the position shown in Fig. 1b without the assistance of the segment 3. As soon as the disc 2 has rotated for a certain angle, the guide-nose 1 engages on the segment 3 which takes over the guiding and locking of the lever 4. r 7

These phases of operation are repeated at every changing-over, the only difference being that the disc 2 is turned alternately in clock-wise direction and reversely thereto. V

i In the modification shown in Figs. 2a 2c, the locking device is formed by two angularly disposed plate springs 20 and 20 affixed to the lever 4 and provided at their lower ends with inwardly directed pins 2| and 2|, each of. which has an oblique end-surface 22, as in Fig. 20. In Fig. 2a the position of the parts is that which they assume immediately prior to the'changing-over of the valves. There are segments 3 and 3' and guide noses 1 and 1' like those in Figs. lal-lc.

The vpins 2|, 2| are above the noses 7, 1 so that said pins will not engage the segments 3, 3' when the lever shifts. In Fig. 2a the guide nose 1' is just being disengaged from the segment 3,, In Fig. 2b the parts are in the position they assume immediately after the changing-over, the guide nose 1 having not yet become engaged with the segment 3 by reason of the larger angular movement of the disk 2. In this position of the parts the changing-over lever 4 is retained by the locking device, in that the oblique end face 22 of the pin 2| has slipped over the segment 3 and has snapped in therebehind, whereby the lever 4 is prevented from turning back into its former poing free ends 23', 23" ,of which are so arranged and bent off and of such a size that when the parts are moved during a changingover operation from the position inFig. 311 into the position in Fig. 3b the spring end 23" slides elastically over the segment 3' (from the right to the-left) and engages its inner side so that the lever 4 is locked in its other position, 'until the guide nose I has become engaged with the segment 3. 'The spring ends 23', 23 are above the guide noses I, I so that said ends '23, 23' will not engage segments 3, 3 when the lever shifts. The spring 23 must be so weak that the shifting of the lever by the spring 8 is not hindered.

In the further modification shown in Fig. 4 the locking device consists of two bell-crank levers 24 and 24 that are looselysupporte'd upon the shaft I which, as has already been mentioned in a preceding part of this specification, is turned to and fro by the gas-meter diaphragm. The bell-crank lever 24 comprises an upwardly directed arm 25 and a laterally directed arm 21, and thebell-crank lever 24' similarly comprises two arms 25 and 21'. The arms 25 and 25 are connected with one another by a helical tension spring 26. Near the free end of each of the arms 21, 21' is a projection 28, the shape and size of which is such that after every changing-over the respective guide nose 29 or 29 of the lever 4 is retained by the projection 28 until that guide nose has become located upon the corresponding segment concernedwhich latter now acts as guide The projections 28 are always engagedmember. by the segments or lugs 3, 3' exceptwhen the bell cranks are depressed by the noses 29 and 29.

In Fig. 4 the parts are in the position they have segments 3 and-3' are shown in the drawing as being in the shape of segmental wedges, however, these elements may also have the same form as the segments 3 and 3' in the other'figures. Owing to the tension of the spring 26 the bell-crank lever 24 contacts with, and is retained'by, the lug 3 (position shown in Fig. 4). At every changing-over a guide-nose concerned depresses the respective bell-crank lever and snaps in behind the corresponding projection 28 so that the lever 4 is again reliably held fast in its new position until the corresponding lug concerned acts as guide member.. l

I claim: v

1. A changeeover mechanism for valves, particularly for dry gas meters. comprising in com bination a change-over lever shiftable between two different end positions, guide noses on said lever, an oscillating disc adapted to control the shifting of said lever, a shaft on which said disc is arranged and which is oscillated by the diaphragm of the gas meter, segments on said disc adapted to engage said guide noses, a spring connecting said lever and disc and adapted to shift the lever from one to the other of its end positions, and a locking device for retaining said noses in their respective end positions until engaged by the cooperating segment.

2. A change-over mechanism for valves, particularly for dry gas meters, comprising in combination a change-over lever shiftable between two different end positions, guide noses on said lever, an oscillating disc adapted to control the shifting of said lever, a shaft on which said disc is arranged and which is oscillated by the diaphragm of the gas meter, segments on said disc adapted to engage said guide noses, a spring connecting said lever and disc and adapted to shift the lever from one to the other of its end positions, and a locking device for retaining said noses in their respective end positions until engaged by the cooperating segment, said locking device comprising a pin attached yieldingly to the change-over lever and having an oblique end face adapted to slide over the cooperating segment when arriving in the new position during the changing over, said end face contacting then with the outer surface of said segment.

3. A change-over mechanism for valves, particularly for dry gas meters, comprising in combination a change-over lever shiftable between two different end positions, guide noses on said lever, an oscillating disc adapted to control the shifting of said lever, a shaft on which said disc is arranged and which is oscillated by the diaphragm of the gas meter, segments on said disc adapted to engage said guide noses, a spring connecting said lever and disc and adapted to shift the lever from one to the other of'its end positions, and a locking device for retaining said noses in their respective end positions until engaged by the cooperating segment, said locking device comprising a plate spring attached to said changeover lever in such a position that an end of the spring slides from the outer to the inner side of the cooperating segment.

a. A change-over mechanism for valves,-particularly for dry gas meters, comprising in combination a change-over lever shiftable between two difi'erent end positions, guide noses onsaid lever, an oscillating disc adapted to control the shifting of said lever, a shaft on which said disc is arranged and which is oscillated by the diaphragm of the gas meter, segments on said disc adapted to engage said guide noses, a spring connecting said lever and disc and adapted to shift the lever from one to the other of its end positions, and a locking device for retaining said noses in their respective end positions until engaged by the cooperating segment, said locking device comprising two bell-crank levers pivoted on said shaft, each of said bell-crank levers having two arms of which one on each lever has a projection adapted tov cooperate with the corresponding guide nose, and a spring connecting the other arms of said bell crank levers.

MAX HELM. 

